This invention relates to fluid flow control instrumentality, and relates more particularly to an improved four-way fluid control valve having a clevis-like metering member similar to that described in U.S. Pat. No. 3,805,835 of Harvey B. Jansen.
The above referenced patent describes a fluid control valve structure which utilizes a bifurcated clevis member that is shiftable across a pair of opposed metering orifices to precisely control fluid flow. In comparison to other types of control valves, the structure referred to reduces the tendency of the metering orifices to clog with contaminants, minimizes mechanical hysteresis of the valve, reduces effort required in actuating the valve, and provides a balanced flow arrangement which substantially reduces power consumed by valve and produces excellent frequency response characteristics. The structure disclosed in the subject patent, however, is directed towards the control of fluid flow only between a passage communicating with the metering orifice and the chamber into which the metering orifice opens.